1 National Food Institute, Technical University of Denmark2 Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark3 Catalan Institute of Oncology4 International Agency for Research on Cancer5 Danish Cancer Society6 Aarhus University7 Centre for Research in Epidemiology and Population Health8 Institut Gustave-Roussy9 German Cancer Research Center10 German Institute of Human Nutrition11 Hellenic Health Foundation12 Cancer Research and Prevention Institute13 Istituto Nazionale dei Tumori14 University of Naples Federico II15 ‘Civile M.P. Arezzo’ Hospital16 Human Genetic Foundation17 National Institute of Public Health and the Environment18 University Medical Centre Utrecht19 University of Tromsø20 Public Health Directorate21 Andalusian School of Public Health22 CIBER Epidemiología y Salud Pública23 Murcia Regional Health Council24 Navarre Public Health Institute25 Lund University26 Umeå University27 University of Cambridge28 MRC Epidemiology Unit29 University of Oxford30 Imperial College London31 International Agency for Research on Cancer32 Danish Cancer Society33 German Cancer Research Center34 German Institute of Human Nutrition35 National Institute of Public Health and the Environment36 Lund University37 Imperial College London
Evidence on the association between dietary flavonoids and lignans and breast cancer (BC) risk is inconclusive, with the possible exception of isoflavones in Asian countries. Therefore, we investigated prospectively dietary total and subclasses of flavonoid and lignan intake and BC risk according to menopause and hormonal receptor status in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. The study included 334,850 women, mostly aged between 35 and 70 years from ten European countries. At baseline, country-specific validated dietary questionnaires were used. A flavonoid and lignan food composition database was developed from the US Department of Agriculture, the Phenol-Explorer and the UK Food Standards Agency databases. Cox regression models were used to analyse the association between dietary flavonoid/lignan intake and the risk of developing BC. During an average 11.5-year follow-up, 11,576 incident BC cases were identified. No association was observed between the intake of total flavonoids [hazard ratio comparing fifth to first quintile (HRQ5–Q1) 0.97, 95 % confidence interval (CI): 0.90–1.04; P trend = 0.591], isoflavones (HRQ5–Q1 1.00, 95 % CI: 0.91–1.10; P trend = 0.734), or total lignans (HRQ5–Q1 1.02, 95 % CI: 0.93–1.11; P trend = 0.469) and overall BC risk. The stratification of the results by menopausal status at recruitment or the differentiation of BC cases according to oestrogen and progesterone receptors did not affect the results. This study shows no associations between flavonoid and lignan intake and BC risk, overall or after taking into account menopausal status and BC hormone receptors.
Breast Cancer Research and Treatment, 2013, Vol 139, Issue 1, p. 163-176